The present invention relates to an impervious, resilient, flexible, biocompatible stent that can be secured in the duodenum adjacent to the pylorus to effect weight loss over a controlled period.
The incidence of obesity and its associated health-related problems have reached epidemic proportions in the United States. See, for example, P. C. Mun et al., xe2x80x9cCurrent Status of Medical and Surgical Therapy for Obesityxe2x80x9d Gastroenterology 120:669-681 (2001). Recent investigations suggest that the causes of obesity involve a complex interplay of genetic, environmental, psycho-behavioral, endocrine, metabolic, cultural, and socio-economic factors. Severe obesity is frequently associated with significant comorbid medical conditions, including coronary artery disease, hypertension, type II diabetes mellitus, gallstones, nonalcoholic steatohepatitis, pulmonary hypertension, and sleep apnea.
Estimates of the incidence of morbid obesity are approximately 2% of the U.S. population and 0.5% worldwide. Current treatments range from diet, exercise, behavioral modification, and pharmacotherapy to various types of surgery, with varying risks and efficacy. In general, nonsurgical modalities, although less invasive, achieve only relatively short-term and limited weight loss in most patients. Surgical treatments include gastroplasty to restrict the capacity of the stomach to hold large amounts of food, such as by stapling or xe2x80x9cgastric banding.xe2x80x9d Other surgical procedures include gastric bypass and gastric xe2x80x9cballoonsxe2x80x9d which, when deflated, may be inserted into the stomach and then are distended by filling with saline solution.
The need exists for cost effective, less invasive interventions for the treatment of morbid obesity.
The present invention provides a novel system for treatment of morbid obesity by use of a bioabsorbable stent fitted snugly in the duodenum adjacent to the pylorus and impervious to digestive juices to limit the uptake of food passing through the stent. The stent is thin-walled, elastic, and flexible so as not to interfere with normal shifting of the duodenum nor with the passage of food therethrough. The stent can be formed of bioabsorbable material such that after a predetermined period the stent degrades and passes out of the body without the necessity for additional surgical intervention.
In the preferred embodiment, the stent includes a weave of bioabsorbable filaments and a covering or coating of impervious material or membrane. Alternatively, the weave can be integrated within the membrane. The filaments preferably have memory characteristics tending to exert moderate pressure against the interior wall of the duodenum, and the stent can possess regional variable strength, structure and bioabsorption pharmacokinetics. The stent can be secured in place by sutures at its proximate and distal ends.